Control system



CONTROL SYSTEM Original Filed April 24, 1951 :5 Sheets-Sheet 1 i g Q2 Nov. 8 1932. M. H. WELLS 1,836,439

- CONTROL SYSTEM Original Filed April 24, 1931 '3 Sheets-Sheet s Miltonli We/15,

Patented Nov. .8, 1 932 UNITED STATES PATENT OFFICE IREGULATO R COMPANY, OF MINNEAPOLIS,

wane

MINNESOTA, A GORPORATION OF DELA- CON'IBOL SYSTEM Application filed April 24, 1931, Serial No. 582,516. Renewed March 28, 1932.

The present application relates to a control system, and more particularly to an electrical system through the medium of which an element may be moved in direct proportion to the degree of movement of another ing drawings.

and remote element. The invention, above stated in its broadest aspect, is capable of innumerable applications, and several embodiments are illustrated in the accompany It is to be understood, however, that the broad idea lying behind all of these embodiments is the idea of mechanism whereby movement of an element in response to variation in some predetermined condition will result in a directly corthe fact, however,

responding movement of an element remote from said first-mentioned element and having no mechanical connection therewith.

To the accomplishment of the above and related objects, my invention may be embodied in the forms illustrated in the accompanying drawings, attention being called to that the drawings are illustrative only, and that change may be made in the specific constructions illustrated and described, so long as the scope ofthe appended claims is not' violated. t Fig. 1 is a more or less diagrammatic view of mechanism constructed in accordance with 39 the present invention;

Fig. 2 is a diagrammatic view of a modification thereof;

Fig. 3 is a similar view of a further modi-. fication; A

Fig. 4 is a diagrammatic viewillustrating 7 one application of mechanism constructed in the present invention;

more or less diagrammatic the application of the operation of a accordance with Fig.5 is a view, in character, illustrating the present invention to 1 valve;

., invention.

Fig. 6 1s a similar view illustrating a further embodiment of my invention applied to the operation of a valve; and Fig. 7 is a' view similar to Fig. 6 but illustra'ting a. still further embodiment of my 1 Referring'more particularly to the drawin Fig. 1 asystem comprising a that I have illustrated ings, it will be seen potentiomproviding tends to move, under ,ter clockwise direction,

eter 1 having its one end connected by a wire 4 to one end of a heating element 2; and having its opposite end connected by a wire 5 to one end of a second heating element 3. The opposite ends of the heating elements are connected to each other through a wire 7 O, to which is connected a line 6 leading to one side of a. source 7 of electrical energy. The opposite side of the source is connected by a wire 8 to a thermostat 9, the free end of which carries a contactor 10 positioned to sweep the potentiometer 1.

Within the heating influence of the heating element 2 there is mounted a heat-responsive element 11, the same being illustrated herein as a bi-metallic strip fixedly mounted at its one end as at'13. The strip 11 is so constructed that its free end tends, under the heating influence of the element 2, to move in a counter clockwise direction.

A second heat-responsive element 12 is mounted within the heating influence of the heating element 3, the element 12 bein herein illustrated as a bi-metallic strip l iaving its one end fixedly mounted as at 14. The strip 12 is so constructed that its free end the heating influence of the element '3, in-a clockwise direction.

A link 15 is formed adjacent its opposite ends with apertures receiving the free ends of the strips 11 and 12, so that said strip ends are connected to each other, and the link 15 is subject to movement under the joint influence of the two strips 11 and 12. The link 15 carries a pointer arm 16 cooperable with a scale 17.

impressed upon the thermostat 9 increases, be moved in a counter clockwise direction across the potentiometer 1, thus reducing the resistance to' current flow through the circuit 7, 8, 9, 10, 1, 4, 2, 70, and 6; and increasing the resistance to current flow through the circuit 7, 8, 9, 10,1, 5, 3, 70, and 6. The heating influence of the heating element 2 is thus in creased, while that o the heating element 3 is decreased, so that the strip 11 is caused to overpower the strip 12, whereby the free ends of both strips are caused to move in a counthus moving the be obvious that scription, of course, presumes that boiler pressure remains a constant during such operation. If, however, the boiler pressure risesbeyond a safe pressure, even though the thermostat 26 is still calling for heat, the contactor 74 will be moved upwardly, thus reducing the resistance to current flow through the circu't 33, 34, 34, 74, 27', 3 30, 28, 73, and 32 and increasing the resistance to current flow through the circuit 33, 34, 34', 74, 27', 31, 31, 29, 73, and 32. If the movement of the contactor 7 4 is such as just to counterbalance the degree of displacement of the contactor 7 2 from neutral position, it will the conjoint effect of the two potentiometers will be to return the lever 38 to the neutral position illustrated. Other phases of the operation of the mechanism herein illustrated will be obvious;

In some of the claims appended hereto, I shall refer to the control mechanism as means for controlling the supply of fuel to a heating unit. The furnace illustrated in Fig. 4 is of the solid-fuel burning type, but it is to be remembered that air admitted through the draft door 43 constitutes a portion of the fuel burned in the furnace; so that it will be seen that the lever 38 and its actuating mechanism is means for controlling the supply of fuel to the furnace 24.

It is to be understood, of course, that, while I have illustrated a system including mechanism for controlling the draft door 43 and the damper 44 in response to the conjoint effects of boiler pressure and room temperature, and while there are advantages in utilizing such a system, nevertheless my invention contemplates the use of a system in which the heaters 28 and 29 shall be subject either to I temperature conditions only or to boiler pres- That is, while I have described a system insure conditions only. shown and have above cluding the potentiometer 27 controlled by the thermostat 26 and the potentiometer 27 controlled by the pressure-responsive mechanism 47, I do not intend to be limited to the conjoint use of both of those potentiometer-s,

since I believe my invention to be broad enough to include the use alone of the potentiometer 27 controlled by the thermostat 26, or the use alone of the potentiometer 27 controlled by the pressure-responsive mechanism 47 Obviously, the embodiment illustrated in Fig. 2 might be substituted for the bellows arrangement of'Fig. 4, the circuit in which the potentiometercoil 19 is connected being arranged to control an electric motor connected to shift the doors 43 and 44.

In Fig. 5, I have illustrated a valve comprising a casing 49 and a second casing 50, the two casings being separated by a flexi ble diaphragm 77. Within the casing 49 there is positioned a valve member 51 controlling the rate of flow of fluid through said casing. A tioned in the casing 50 to fluid through the casing,

members 51 and 52 are connected for dependent movement through the medium of a stem 53. The stem 53 projects upwardly through the casing 50 and through a second flexible diaphragm 78 closing the upper end of the casing 50.

A thermostat 54 is mounted at a remote point,-a movable element of said thermostat carrying a contactor 55 disposed to sweep a potentiometer 56. One end of the potentiometer 56 is connected, by a wire to one end of a heating element 57 the opposite end of said element being connected by a wire 81 to one end of a second heating element 82. The opposite end of the heating element 82 is'connected by a wire 83 to the opposite end of the potentiometer 56. A source 84 of electrical energy has its one side connected by a wire 85 to the wire 81, and has its opposite side connected by a wire 86 to the thermostat 54, and so to the contactor 55.

A frame or bracket 87 is mounted at thi upper end of the valve casing 50 and carrie a bellows 58, the lower end of which is secured to the bracket 87. A second bellows 79 has its upper end secured to the bracket 87. The upper end of the bellows 58 and the lower end of the bellows 79 engage opposite faces of a disc 59 connected to the upper end of stem 53.

One use for the organization illustrated herein is in the control of fluid and air supply to a fluid fuel burner. In this organization, the flow of air may be controlled through the casing 50, and the flow of fluid fuel may be controlled through the casing 49. Upon a call for heat by the thermostat 54, the contactor 55 is moved upwardly to reduce the resistance to current flow through the circuit 84, 86, 54, 55, 56, 80, 57, 81, and 85; and to increase the resistance to current flow through the circuit 84, 86, 54, 55, 56, s3, s2, 81, and 85; thus expanding the bellows 58 to elevate the stem 53, thus increasing the effective port areas controlled by the valvemembers 51 and 52.

In Fig. 6 there is illustrated a valve casing 88 controlled by a valve member 63 cooperating with the port 64 through the usual par tition. A stem 62 is connected to the valve head 63, said stem passing through a flexible diaphragm 89 closing the upper end of the casing. A bracket 90 is mounted upon the upper end of the casing. and a bellows 60 has its upper end secured to the bracket 90, while a second bellows 61 hasits lower end secured Y and 70 surround, respectively,

is connected by a Wire 96 to the'opposite end;

of the potentiometer 93. A wire 97 com nects the wire 95 toone side of 'a current source 98, the opposite side of which is connected by a wire 99 to the thermostat 71, and so to the contactor 92. The. heating units 69 a pair of capsules 65 and 66. The capsules artially filled with a volatile liquid, and the bellows 60 and 61 are completely filled with the same volatile liquid. The capsule 65 is connected to the bellows 60 by a tube 67,

and the capsule 66 is connected to the bellows 61 by a tube 68. Preferably the heating elements 69 and 7 0 are surrounded by insulating material.

If the temperature impressed upon the thermostat 71 drops below the desired mini vmum, the thermostat moves the contactor 92 upwardly, thus reducing .the resistance to current flow through the circuit 98, 99, 71, 92,93, 96, 70, 95, and 97, and increasing the resistance to current flow through the circuit 98, 99, 71, 92, 93, 94, 69, 95, and 97. The degree of energization of the heater 70 is thus increased, while that of the heater 69 is decreased, so that a greater proportion of the fluid in the capsule 66 is vaporized, while a lesser proportion of the fluid in the capsule 65 is vaporized. Thus the bellows 61 is expanded by liquid pressure, while the bellows is collapsed by the reduction of the pressure therein, and the, valve 63 is moved upwardly-to'iapenposition. I

The embodiment illustrated in F g. 7 1s in all respects identical with that illustrated in Fig. 6 except that I have substituted there- -'in a thermostat 72 of the volatile fluid type tactor 100 positioned to swee for the bi-metallic type of Fig. 6. The thermostat 72 carries a cona potent1- ometer 101 suitably connected in the circuit controlling the heaters 69 and 70. The operation of this device is identical with that illustrated in Fig. 6.

It will be obvious that one of thefeatures K v which is common to all of the embodiments illustrated herein is the lack of responsiveness of any one of the illustrated systems to temperature variations in the ambient medium surrounding or impressed upon the temperature responsive elements In the embodiment of Fig. 1, for instance, a variation in the temperature of the atmosphere surround ing. the elements 11 and 12 will be impressed onlboth of said elements; and, since said ele ments tend to respond oppositely to a temperature change, the mem er 15 and the indicator 16'wil-l not be moved by such a variation.- That is, if the temperature of the 813-.)

member 15 would not ap lies to other embodiments.

and 66 are' thermostat 71 of said heat responsive elements .source of electrical energy,

.12 should rise, the element 11 would tend to move upwardly, but the element 12 would tend to move downwardly, and the tendency of the element 12 would exactly neutralize the tendency of the element 11, so that the be moved. The same imilarly, a variation in the voltage of the current source in any one of the embodiments willnot affect the controlled element, since the two oppositely acting heat responsive elements will be oppositely affected in the same de 'ree.

f claim as my invention:

1. The combination with a source of electrical energy,.of a pair of electrical heating units connected in parallel to one side of said source, a movable contactor connected to the other side of said source, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said heating units respectively, a heat responsive element disposed within the influenceof each of said heating units, and means associated with said heat responsive elements and movable under the joint influence thereof.

2. The combination with a source of electrical energy, of a pair of electrical heating units connected in parallel to one side of said source, a movable contactor connected to the other side of said source,

a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said ture thereof, a heat responsive element dis- I posed within the influence of the other of said heating units and movable in the opposite direction in response to a rise in temper'ature" thereof, and means associated with and movable under the joint influence thereo 3. The combination with a source of electrical energy, of a pair of electrical heating elements connected in parallel to one side of said source, a movable contactor connected to the other side of said source, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said heating elements, respectively, a heat responsive member movable in one direction by one of said elements, a second heat re-v of said members and'movable under the joint influence thereof.

4. The combination with a heating plant, of means for controlling the supply of-fuel to said plant, said means comprising a a pair of electrical heating elements connected in parallel source, a potentiometer positioned to one side of said source, a movable con- ,tactor connected to the other side of said to e swept by said contactor and having its opposite ends connected to said elements, respectivel a heat responsive member movable in one irection by one of said elements, a second heat responsive member movable in the opposite direction by the other of said elements, and means connected to control said fuel-supply controlling means, said lastnamed means being associated with both of said heat responsive members and movable under the joint influence thereof.

5. The combination with a heating plant, of means for controlling the supply of fuel to said plant, said means comprising a source of electrical energy, a pair of electrical heating elements connected in parallel to one side of said source, a movable contactor connected to the other side of said source, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said elements, respectively, a heat responsive member movable in one direction by one of said elements, a heat responsive member movable in the opposite direction by the other of said elements, electrical means for shifting said, fuel-supply controlling means, a circuit therefor, and means associated with both of said members and movable under the joint influence thereof for controlling said last-named circuit.

6. The combination with a heating plant, of means for controlling the supply of fuel to said plant, said means comprising a source of electrical energy, a pair of electrical heat ing elements connected in parallel to one side of said source, a thermo-responsive element, a contactor carried by said element and connected to the other side of said source, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said elements, respectively, a heat responsive member movable in one direction by one of said elements, a heat responsive member movable in the opposite direction by the other of said elements, and means connected to control said fuel-supply controlling means, said last-named means being associated with both of said members and movable under the joint influence thereof.

7. The combination with a heating plant, of means for controlling the supply of fuel to said plant, said means com rising a source of electrical energy, a pair 0 electrical heating units connected in parallel to one side of said source, a thermo-responsive element, ,a contactor carried by said element and connected to the other side of said source, a podzentiometer positioned to be swept by said contactor and having its opposite ends connected to said units, respectively. a heat-at jected member movable in one direction by 85 one of said units, a heat-affected member ing associated tively,

movable in the opposite direction by the other of said units, electrical means for shifting said fuel-supply controlling means, a circuit therefor, and means associated with both of said members and movable under the joint influence thereof for controlling said. lastnamed circuit.

8. The combination with a heating plant, of means for controlling the supply of fuel to said plant, said means comprising a source of electrical energy, a pair of electrical heating units connected in parallel to one side .of said source, a pressure responsive element, a contactor carried by said element and connected to the other side of said source, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said units, respectively, a heat responsive member movable in one direction by one of said units, a second heat responsive member movable in the opposite direction by the other of said units, and means connected to control said fuel-supply controlling means, said last-named means bewith both of said members and movable under the joint influence thereof.

9. The combination with a heating lant, of means for controlling the supply 0 fuel to said plant, said means comprising a source of electrical energy, a pair of electrical heating units connected in parallel to one side of said source, a pressure responsive element, a contactor carried byv said element and connected to the other side "of said source, a potentiometer'positioned to be swept'by said contactor and having its opposite ends connected to said units, respectively, a member movable in one direction by one of said units, a member movable in the opposite direction hi the other of said units, electrical means for s ifting said fuel-supply controlling means, a circuit therefor, and means associated with both of said members and movable under the joint influence thereof for controlling said last-named circuit. p

10. The combination with a heating plant, of means for controlling the supply of fuel to said plant, said means com risin a source of electrical energy, a pair 0 electrical heating elements connected in parallel to one side of said source, a movable contactor connecte to the other side of said source-and responsive to a condition created by said heating plant, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to said heating elements, respeca thermo-responsive member movable in one direction under the heating influence of one of said heating elements, a thermo-responsive member movable in the opposite direction under the heating influence of the other of said heating elements, and means connected to control said fuel-supply controlling means, said last-named means being associated with both of said members and mov able under the joint influence thereof.

. sald to on side of said source,

11. The combination with a furnace, of draft control means therefor comprising a source of electrical ener a pair of heat1n elements connected in parallel to one side 0 source, a thermostat arranged within the heating influence of said furnace, a contactor carrie by a movable element of said thermostat and connected to the other side of said source, a potentiometer positioned to be swept by said contactor, and having its opposite ends connected to said heating elements, res ectively, a member expansible under the inuence of heat and disposed within the heating influence of one of said heating elements, said member being rigidly supported at one end only, a second member expansible under the influence of heat and disposed within the heating influence of the other of said heating elements, said second member being rigidly supported at one end only andhaving its free end disposed in opposed juxtaposition to the free end of said first member, a pivoted lever associated with and movable under the joint influence of said two members,.and means operatively connecting said lever to a draft door of said furnace. v

12. The combination with a furnace, having a boiler, of draft control means therefor comprising a source 20f electrical energy, a

pair of heating elements connected in parallel apressure-responsive mechanism, means connecting said pressure-responsive mechanism to whereby the pressure in said boiler is impressed upon-said pressure-responsive mechanism, a contactor carried by, a movable element of said pressure-responsive mechanism and connected to-the other side of said source, a potentiometer positioned to be swept Elly said contactor, and having its opposite en s connected to said heating elements, respectively, a member expansible under the influence of heat and disposed within the heating influence of one of said heating elements, said member being rigidly supported at one end only, a second member expansible under the influence of heat and disposed within the heating influence of the other of said heating elements, said second member being rigidly supported at one end only and having its free end dis 'osed in opposed juxtaposition to the free en of said first member, a pivoted lever associated with and movable under the joint influence of said two members, and meansoperatively connecting said lever to a draft doorof said furnace. I

13. The combination with a furnace having a boiler, of draft control means for said fur nace comprising a source of electrical energy, a pair of heatin elements connected in parallel to one side osaid source, a thermostat arranged within the heating influence of said furnace,

a boiler, fsaid boiler hand at Wabash, Indiana a contactor carried by a movable element of said thermostat and connected to the other side of said source, a potentiometer positioned to be swept by said contactor and having its opposite ends connected to sald heating elements, respectively, a pressure-responsive mechanism, means connecti (f said pressure-responsive mechanism to'sai boilor whereby the pressure in said boiler is impressed upon said pressure-responsive mechanism, a contactor carried by a movable element of said pressure responsive mechanism and connected to-said last-mentioned side of said source a second potentiometer positioned to beswept by said last-named contactor and having its opposite ends connected to said heating'elements in with said first potentiometer, a mem r exarallel pansible under the influence of heat and disposed within the heating influence of said heating elements; said member being rigidly supported at one end only, asecon member expansible under the influence of heat and disposed within the heating influence of the other of said heating elements, said second member being rigidly supported at one end only and having its free end dis-' posed in opposed juxtaposition to the free end of said first member, and means associated with both of said expansible members and movable under the joint influence thereof, said means being operatively connected to a'draft door of said furnace. v

a 14. The combination with a furnace having of means operatively connected to a draft door of said furnace, and mechanism connected to control said means, said mecha-. nism comprising two electric heating units, two heat responsive elements respectivel under the control of said units, one of sai eles1ve means subject to pressure conditions in said boiler and connected likewise to aflect current flow through said two units.

15. The combination of two opposed heatresponsive elements, means associated with sai heaters, one for each of said heat-res onsive elements, and an energizing circuit or said heaters comprising ad ustable means for inversely proportioning energization of i said heaters. I

In witness whereof, I'have hereunto set my this 17 day of April, A. D. one thousand nine hundred and thirty-one.

' MILTON ,H. WELLS.

one ofheat-responsive elements and movable. under the oint influence thereof, two electric Nov. 8, 1932. F. A. DELANO CORRUGATED TRANSPARENT MATERIAL Filed D60. 26, 1928 

